Prevalence of Gastroesophageal Reflux Symptoms in Asthma* Stephen K Field, MD; Margot Underwood, RN;f Rollin Brant, PhD; and Robert L. Cowie, MD Study objective: To determine the prevalences of symptomatic gastroesophageal reflux (GER), reflux- associated respiratory symptoms (RARS), and reflux- associated p-agonist inhaler use in asthmatics. Design: Questionnaire-based, cross-sectional analytic survey. Setting: Outpatient asthma and clinical research clin¬ ics attached to the University of Calgary tertiary care centre and two family practices. Patients: Asthma group consisted of 109 patients re¬ ferred to an outpatient asthma clinic. First control group consisted of 68 patients visiting their family physicians. Second control group consisted of 67 patients with thyroid disease, hypercholesterolemia, or diabetes participating in drug trials. Results: Among the asthmatics, 77%, 55%, and 24% experienced heartburn, regurgitation, and swallowing difficulties, respectively. Symptoms were less preva¬ lent in the control groups. At least one antireflux medication was required by 37% of asthmatics (p<0.001, vs controls). None of the asthma medications were associated with an increased likelihood of symp¬ tomatic GER. In the week prior to completing the questionnaire, 41% of the asthmatics noted RARS, in¬ cluding cough, dyspnea, and wheeze and 28% used their inhalers while experiencing GER symptoms. In¬ haler use correlated with the severity of heartburn (r=0.28, p<0.05) and regurgitation (r=0.40, p<0.05) Conclusions: The questionnaire demonstrated a greater prevalence of GER symptoms, RARS, and re¬ flux-associated inhaler use in asthmatics. This exces¬ sive inhaler use may explain how GER indirectly causes asthma to worsen. (CHEST 1996;109:316-22) BMI=body mass index; GER=gastroesophageal reflux; NS=not significant; PEFR=peak expiratory flow rate; RARS=reflux-associated respiratory symptoms Key words: asthma morbidity and mortality; p-agonist; bronchial hyperreactivity; bronchodilator; cough; dyspnea; esophagitis; gastroesophageal reflux; heartburn; regurgitation TPhe association between gastroesophageal reflux ¦*¦ (GER) and asthma has been reported repeatedly over the last 30 years.1"6 The reasons for the strong association are not fully understood. Studies from the 1960s and 1970s of patients referred for evaluation and treatment of hiatal hernia and GER indicated that respiratory symptoms, including asthma, were preva¬ lent in this population and improved after successful esophageal surgery.1"4 At that time, the diagnosis of GER was confirmed by GI contrast radiographs and fluoroscopy. More recendy, ambulatory pH monitor¬ ing has proved to be more sensitive and specific and has become the diagnostic standard for GER.7 It can demonstrate abnormal GER even in asymptomatic patients.8 A recent ambulatory pH monitoring study of asthma patients demonstrated that more than 80% *From the Division of Respiratory Medicine, University of Calgary and the Calgary Asthma Program, Calgary, Alberta, Canada, f Salary support in part by the Alberta Lung Association and Fisons Pharmaceuticals (Ms. Underwood). Presented in abstract form at the Annual Meeting of the Ameri¬ can Thoracic Society, Boston, May 22-25, 1994. Manuscript received August 10, 1995; accepted September 19. Reprint requests: Dr. Field, Foothills Hospital, 1403 29th Street NW, Calgary, Alberta T2N 2T9, Canada have abnormal GER.9 However, the prevalence of symptomatic GER in asthma is unknown. Ekstrom and coworkers10 reported the results of antireflux therapy in 50 patients with symptomatic re¬ flux selected from 350 moderate to severe asthmatics. However, it is not clear whether these were the only patients with reflux symptoms. If so, it would suggest that approximately 15% ofasthmatics experience symp¬ tomatic reflux. Approximately half of the 50 patients with symptomatic reflux had reflux-associated respira¬ tory symptoms (RARS). Recently, Sontag and coworkers11 reported that 40% of asthmatics have endoscopic evidence of erosive esophagitis; therefore, it would be expected that the prevalence of reflux symptoms would be greater than that reported by Ekstrom et al.10 The purpose of the present study was to estimate the prevalence and severity of GER symptoms in the population of asthma patients attending our clinic, determine the association of asthma medication use with symptomatic GER, the prevalence of RARS, and the association of GER symptoms with increased bronchodilator use. 316 Clinical Investigations Downloaded From: http://journal.publications.chestnet.org/pdfaccess.ashx?url=/data/journals/chest/21727/ on 06/26/2017